Differential gears are generally constructed as planetary wheels, and most commonly serve the purpose of splitting or distributing an input power, supplied by a power input, to two drive shafts. Differential gears are most frequently used in the building of automobiles as so-called axle differentials. In this case, drive power supplied by a drive motor is distributed via the differential gear to wheel drive shafts of driven wheels. The two wheel drive shafts leading to the wheels in this case are each driven at the same torque, meaning they are balanced. When the vehicle drives straight forward, both wheels rotate at the same speed. When the vehicle travels a curve, the rotation speeds of each wheel are different. The axle differential makes this rotation speed difference possible. The rotation speeds are able to adjust themselves freely; only the average of the two speeds is unchanged.
In certain applications, particularly in all-wheel drive vehicles, differential gears are used which enable a switchable decoupling when the all-wheel drive function is not necessary, and additionally enable a separation in the drivetrain in order to drive the vehicle via only one axle, thereby reducing friction loss in the drive system, the same being not necessary at the moment, but otherwise driven anyway. Such a differential gear is known from DE 10 2008 037 885 A1, by way of example.
The problem addressed by the invention is that of creating a differential gear which enables a switchable release of the drive connection between the power input and the two power outputs, and which is characterized by a robust construction which can be realized in a cost-effective manner, wherein the differential gear generates the least possible drag torque when idling—meaning when the connection between the power input and the two power outputs is released.